High-speed hydraulic press



June 5, 1928. 1,672,561

w. ERNST HIGH SPEED HYDRAULIC PRESS Filed Sept. 29, 1926 2 Sheets-Sheetl SW 1. Tar-k 3 i 62 Ir 5 ll I r J-T 1| ,f belzibl' Walter Errufli June5, 1928. 1,672,561

W. ERNST HIGH SPEED HYDRAULIC PRESS Filed Sept. 29, 1926 2 Sheets-Sheet2 S ge Ilnk Boosier- Main C i nder- Boo s'l'cr Hale. Discharga 'Pum jectthe Fatented June 5, 1928.

1 UNITED war, or MOUNT sum, 0x10, assronoa'r'o 'rna muons amassIANUFACTURING COMPANY, OF MOUNT GILEAD, OHIO HIGH-SPEED HYDRAULIC PRESS.

Application filed September 29, 1928. Serial No. 138,416.

This invention relates to hydraulic presses which are intended to beoperated by fi u1d sup lied under pressure from a reversible variabledelivery pump and has for an obprovision of simple and effic ent valvemechanism by which the propersequence of operations will be carried outantomatically or semi-automatically. Detail features of the inventionwill be apparent from the following description and t e appended claims.i

This invention relatesto certain improvements on applicants Patent1,653,350, of December 20, 1927. i

In the drawings: Y

Figure 1 is a side elevation of one'type of press having embodiedtherein the present invention.

Figure 2 is a. vertical section through a valve mechanism constituting apart of the .invention.

Figure 3 is a diagrammatic view with two valve mechanisms shown insection showing the various connections from the pump to the operatingmechanism of the press.

The invention may be embodied in various types of presses employed forvarious purposes, but is illustrated in connection with a press of thefour column downward pressure type. 4 which may be formed of cast ironfor the purpose of bringing the working surface to a convenient height.Above this is a heavy cast steel base B which receives the strains fromthe press. A- press head C is con- 4 nected to the base by-four strainrods D.

The main'downwa'rdly movable platen E is guided on the strain rods inthe usual manner. There is also illustrated in Figure 1 a variabledelivery reversible pump F and connections for operating the same whichform no part of the present invention.

A pipe line 1 is shown as leading from the pump and has a branch 2 whichcommunicates with two booster cylinders 3 which are intended to initiatethe movement of the press ram. This line also has a connection 4 leadingto a valve mechanism generally indicated at 5. From this valve mechanisma pipe 6 communicates with the main cylinder 7 above the press ram. Fromthe upper part of this cylinder a pipe 8 communicates by the 'way of avalve mechaplate 36., the position of which may be adnism indicatedgenerally at 9 with a surgetank 10, which has a pipe 11 communicatingwith the valve mechanism 5.

A second pipe 12 leads from the pump F and has a separate branch 13communicating with the two ush back cylinders 14 which return the p atento its upper position. This line 12 alsohas a line 15 which-com--municates with a small'chamber underlying the stem of the valve mountedin t-he'valve mechanism 9 above mentioned- The pipe 12 also communicateswith the valve mecha nism 5. i I

The valve mechanism 5 is particularly illustrated in Figure 2 butcomprises a main casting 16 which is divided into four chambers 17, 18,19, and 20. Apartition 21 between the chambers 17 and 18 is providedwith a plurality of passages 23 and the partition '22- between thechambers 18 and 19 is provide'd with similar passages 24. A valve stem26 is slidably mounted in the partitions 21 and 22 and carries at oneend a head 27 lying in the chamber 19 and is adapted to close theopenings 24 and at its other end a head 28 lying in the chamber 17 isadapted to close the openings 23. The valve stem is of such length thatwhen one set oi openings is closed the other is opened.

There is shown a base A TAls'o slidably mounted in the'casing is a valve29-which coacts with a valve seat 30 to control communication betweenthe chambers 17 and 20. The upper end of this valve stem is guided in abushing 31 set in the casing 16 and acting to retain a packing 32. Thelower end of the valve stem has a pack-" ing 33 held in place by acylindrical member 34 which is screwed into the casing 16.

- This member 34 has mounted therein a coil spring 35, and bears at oneend against the valve'stem and at. its'other end against apisted by ascrew 37 adjustably mounted in a cap 38 which is screw threaded on theopen end of the member 34. In this manher the tension of the spring maybe varied and the valve set to open at differing pressures. The valvemechanism 9 comprises a casing 39 having therein a passage 40 which iscontrolled by a valve {11. The stem 42 of this valve is separate andfits slidably in a short tubular member which is connected to the ms v ycommunicates with the chamber 17 will thus 7 vis set to deliver fluidend of'the pipe 15. Suitable packing 43 is provided and a small chamber44 is formed in the tubular member just mentioned. A

perend against a fixed collar through which the valve stem 42 tends tohold the tion.

The operation of the device may be described as follows. It is assumedthat it is desired to operate the press. The pump under pressure throughThe branch 4 of this line which slides so that this spring stem 42 inits lower posithe' line 1.

receive fluid under pressure and the valve stem 26 will slide to theright in Figure 8 so thatthe valve head 28 closes communicashown in thisfigure.

tion between the chambers 17 and 18 as At the same time,

-- fluid under pressure will pass through the through the valve casing 9branch pipe line 3 and thus start 1 '29 will then be moved downwardlyfrom the valve seat 30, opening communica- "chamber 1 main cylinder 7.As soon as the fluid under "high pressure enters the main cylinder 7,

' 8 will close the valve 41 2 I to the booster cylinders upper portionof the main cylinder 7, but the suction exerted through the pipe 8 willlift the valve 41 off its seat against the force of gravity and permitliquid to flow from the surge tank 10 and pipe 8 into the upper. portionof the main cylinder 7 behind the press mm. This action will continueuntil the ram meets suflicient resistance to build up the pressure inthe pipe line 1 to a point where it is sufficient to overcome the forceof the spring 35. The valve away tion between the chambers 17 and 20 andthe chamber 20, and pipe 6 into the the back pressure exerted throughthe pipe and prevent this fluid from returning to the surge tank'at thistime. The parts will remain in this position until the pressingoperation is completed.

Thereafter, either automatically or .man

ually, the pump will be reversed and discharge fluid under pressure intothe pipe line 12. The branch 13 of this line will con duct fluid to thepush back cylinders 14 and immediately begin returning the ram'to its'normal upper position. At the same time the fluid entering the chamber19 will move the valve stem 26 to the left so that the head 27 willclose communication between the chambers 19 and 18. At this time thefluid under pressure will also pass through the branch 15 to the underside of the valve stem 42 and exert suflicient pressure thereon to liftthe valve 41 off of its seat and permit the movement of the press. I ramdownwardly. This, of course, tends to produce a vacuum in the ass fromthe pipe 4 through the 1 directly to the tank 10. As soon as the pressram reaches.

its upper normal position, the pump may be stopped manually orautomatically or re versed to begin a new pressing operation.

It is to be noted that during this return movement, the booster ramswillalso be moving upward in the booster cylinders 3 and the fluidcontained in these cylinders will be forced through the pipe line 2 andbranch 4 into the chamber 17 and thence into chamber 18 and through thepipe 11 to the surge tank.

It is obvious that the invention is independent of any specific type ofpump so long as it is adapted to be reversed and afford a variabledelivery. WVhile especially adapted to a high speed press, the inventionmay be applied to presses of many kinds without departing from thespirit thereof. It is obvious that features of the invention may bemodified as regards their specific embodiment and it is to be rememberedthat the invention is limited only by the scope of the appended claims.

I claim as my invention:

1. In a hydraulic press mechanism having main, booster, and pushbackcylinders, a press ram operated thereby and a surge tank; operatingmeans which comprises a pipe line for conducting fluid under pressure tothe booster cylinders, connections from the main cylinder to the surgetank including a valve which automatically opens when the fluid entersthe booster cylinders, and connections from said pipe line to the maincylinder including a second valve which opens when the pressure in saidpipe ine reaches a predetermined point and admits fluid under pressurefrom'said pipe line main cylinder.

2. In a hydraulic press mechanism having main, booster, and push backcylinders, a press ram operated thereby and a surge tank; operatingmeans which comprises a pipe line for conducting fluid under pressure tothe booster cylinders, connections from the main cylinder to the surgetank including a valve which automatically opens when the fluid entersthe booster cylinders,

.and connections from said pipe line to .the

main cylinder including a second valve which opens when the pressure insaid pipe predetermined point and ad-.

line reaches a mits fluid under pressure from said pipe line directly tothe main cylinder.

3. In a hydraulic press mechanism having main, booster, and push backcylinders, a press ram operated thereby and a surge reaches apredetermined point and admits fiuid under pressure from said pipe linedirectly to the main cylinder, a. pipe line for admitting fluid underpressure to the push back cylinders to return the press rum,

in the second pipe line for opening the first named valve and permittingfluid to returnfroin the main cylinder to the surge tank, and anothervalve opened by pressure in said second pipe line and interposed inconnections between the booster cylinders and the surge tank whichpermits fluid to return to the surge tank from the booster cylinders atthis time.

In testimony whereof, I have hereunto ubscribed my name. means operatedby the fluid under pressure:

WALTER ERNST.

